Continuous magnetic recording system



July 22, 1947. H. NYGAARD CONTINUOUS MAGNETIC RECORDING SYSTEM Fiied March 2, 1945 3 Sheets-Sheet l WW M M m H ATTORNEY July 22, 1947. H. NYGAARD 2,424,498

CONTINUOUS MAGNETIC RECORDING SYSTEM Filed March 2, 1945 3 Sheets-Sheet 2 O t v v 1 L /fl 0742; w FJ/ 9 w a, M 11 .--422 o ETCS w 7* Eds WW ATTORNEY July 22, 1947. H, NYG ARD 2,424,498

CONTINUOUS MAGNETIC RECORDING SYSTEM 9/ u. w Z w V 1.7 O O O O 1 INVENTOR. //J flfi M bffiMA/V mama B Mi /Zf W W4 W A TTORNEY Patented July 22, 1947 CONTINUOUS MAGNETIC RECORD'ENG STEM Herman Nygaard, East Orange, N. J., assignor, by mesne assignments, to Lear, Incorporated, Grand Rapids, Mich a corporation of Illinois Application March 2, 1945, Serial No. 580,625

18 Claims. 1

This invention relates to continuous magnetic recording systems, and more particularly to a novel rugged interchangeable magazine containing the recording wire medium, particularly adapting such system for use aboard aircraft.

In accordance with the present invention, light weight, rugged, compact and easily stored magazines are provided each containing a recording head, recording wire and reeling means for the wire. readily contained in a relatively small magazine. These magazines are adapted for rapid and interchangeable use with a simple, light weight and rugged sound recording or "flight unit carried aboard the aircraft. Each magazine is capable of recording for more than one hour before its recordin capacity is exhausted. The magazine is then quickly detachable from the recording unit and quickly replaceable by a similar magazine. The recording unit may be connected to a microphone used by an observer or may be connected with the intercommunication system or radio of the aircraft. Thusv a practically continuous record is available for any length of time desired. The magazines used are rugged,,compact, light weight and easily stored.

At the conclusion of the mission, the magazines are placed, in proper sequence, in interchangeable cooperation with a sound recording and reproducing, or ground .unit, where the recordings are directly played back" to furnish a complete record of the oral observations and comments of the crew members during the mission. Subsequently, the magazines may be stored for future reference or the recordings therein may be magnetically erased and the magazine reused.

A recording length of an hour may be.

The magazine of the present invention includes a. novel spooling arrangement for feeding the magnetic recording wire to and from a pair of reels. er arm assembly upon which the recording or translating head is rigidly mounted. The magazine is a compact yet rugged unit that faithfully records and reproduces sound even under severe The spooling mechanism embodies a rock- 7 vibration or operating conditions, such as enthe translating unit whe such latch is released. It is among the objects of this-invention to providea simple, rugged, light-weight compact magazine for interchangeable use with magnetic sound recording or reproducing units, to provide such a magazine containing a minimum number oi essential components for operation in severe service conditions; to provide such a magazine adapted for easy economical and compactstorage;

to provide such a magazine containing a magnetic translating head, a linear magnetic recording medium, reeling means for traversing the.

medium through the head, and-a novel spooling unit for properly disposing the wire on the reeling means; to provide such a. unit including an able to couple the magazine onto a sound translating unit; to provide a sound translating unit including novel parallel ejecting means for displacing a magazine therefrom upon release of the latch means contained in the magazine; to

provide a sound translating unit containing driving mechanism for operating reeling means in a magazine cooperable therewith and agear reduction unit for operating a spooling' unit in the magazine at a reduced rate with respect to the reeling means; and to provide a continuous magnetic sound translating system, requiring no threading of the recording wire for usin Presenting a minimum risk or wire breakage,and including rapidly. interchangeable magazines adapted for easy and economical storage.

These and other objects, and novel features of the inventionwill be apparent from the following description and the accompanying drawings. In the drawings: Fig. 1 is a perspective view oi a sound translat ing unit and a magazine arranged in operative relation therewith.

Fig. 2 is a top plan view oi! the sound translating unit shown in Fig. 1.

Fig. 3 is a longitudinal sectional view on the line 3+3 oi Fig. 2 looking in the direction of the arrows.

Fig. 4 is a view on the line 4-4 0! F18. 3 illustrating a gear reduction unit included in the sound translating unit.

Fig. 5 is a top plan view or the magazine with the cover removed.

Fig. 6 is a longitudinalsectional view on the line 6-6 of Fig. looking in the direction of the.

arrows.

Fig. '7 is a cross-sectional view on the line 1-1 p of Fig. 5 looking in the direction of the arrows.

Fig. 8 is a plan view of a spooling mechanism incorporated in the magazine.

Fig. 9 is an elevational view of the spooling mechanism shown in Fig. 8, illustrating associated parts of the magazine in section.

Fig. 10.is an elevation view, partly in section, illustrating an elapsed time indicator forming part of the invention.

Generally speaking, the system of the invention includes a magazine unit adapted for ready interchangeable operation with any one of a plurality of sound translating units. The magazine unit includes an electromagnetic translating head, reeling means for transversing a sound recording medium with respect to such recording head, and novel spooling mechanism, common to both reeling means, for feeding the recording medium onto and ofi the reeling means without injuring the recording medium. An electrical coupling or connection member is electrically connected to the recording head, and mechanical coupling elements are operatively associated with each of the reeling means and with the spooling mechanism. By translating head, as used hereinafter in the specification and claims, is meant a device operable either to impress magnetic impulses on the recording medium or wire or to convert impulses from the wire into electrical sound impulses. It is thus a recording and reproducing head. Y

The translating units include translating mechanisms for converting sound impulses into magnetic impulses imposable on the recording medium or wire in the magazine. An electrical conmotionor coupling member is associated with the translating mechanism for cooperation with the complementary element on the magazine. The translating units also include driving mechanism, having mechanical coupling elements as sociated therewith for detachable engagement with the mechanical coupling elements of the magazine. Gearing is provided in association with the driving mechanisms for operating the spooling mechanism of the magazine at a reduced speed with respect to the reeling means thereof. Referring to Fig. 1, the system of the invention includes a magazine l5 electrically and mechanically cooperable with a sound translating unit 20. Magazine I5 is substantially rectangular in shape and unit 20 is provided with a forward section II extending upwardly above a rearward or base section l2 to a height substantially equal to the thickness of magazine I5. When magazine I5 is placed in cooperative relation with unit 20,

the combined unit has a substantially rectangular outline. Magazine I5 is provided with flat -perpendicularly related sides, thereby adapting it for convenient and economical storage.

Translating unit 20 illustrated in Fig. 1 is adapted for airborne use, and contains means for translating sound impulses from a microphone 13 into magnetic impulses imposable upon a linear magnetic recording medium or wire contained in magazine IS. A cable It connects microphone l3 to a jack l6 cooperable with a plug II on unit 20. Unit 20 is provided with suitable control switches l8 and 2|, anindicating light 22. an indicating level meter 23, and an electrical coupling member 2| for coupling the unit to a. suitable source of electrical energy.

Magazine i5, as will be described more fully hereinafter, contains a pair of reels for moving a magnetic recording wire with respect to a magnetic translating head, and spooling mechanism for feeding the wire in uniformlayers to and from the reels. The magazine also contains an elapsed time indicator comprisin a needle cooperable with a scale 25 on a window 26 in cover 21 of the magazine. An erasing coil is also mounted in the magazine. This coil and the translating head are electrically connected to an electrical socket in "the base of magazine l5, and are electrically connected to the circuits in unit 20 through an engaging plug on unit 20. Similarly, the reels are each provided with mechanical coupling means on the base of magazine I5 cooperable with mechanical coupling elements on unit 20, as is also the spooling mechanism unit. The electrical and mechanical-coupling means of the magazine are recessed within the magazine adjacent apertures in the base and the outer surfaces of such means are substantially coplanar with the outer surfaces "of the base, as will be described in more detail hereinafter.

Translating unit 20 contains driving mechanism for operating the reeling means and reduction gearing operable by the driving mechanism for operating the spooling mechanism at a reduced rate with respect to the reeling means. By disposing the reduction gearing for the spooling mechanism in unit 20, a reduction in weight is achieved in magazine l5, as well as a decrease in the components carried therein, contributing to the simplicity and compactness of the magazine. Unit 20 also includes a suitable recording circuit operable to convert sound impulses into electrical impulses which are electrically transmitted to the translating head in magazine IS. The electrical and mechanical coupling elements of unit 20 project above the surface of section I2 thereof for entry into the base apertures of magazine 50 for cooperation with electrical and mechanical coupling means of the magazine, as will be described in detail. Furthermore, unit 20 is provided with locating pins and a latching pin, the latter being cooperable with an automatically operable latch on the magazine for retaining the magazine in position on the unit when it is placed in operative relation therewith. An automatically operable parallel ejecting mechanism is provided in unit 20 for displacing magazine l5 with respect thereto upon release of the magazine latching means so that the magazine may be quickly detached from the translating unit.

Translating unit 20 and its components, are more clearly illustrated in Figs, 2, 3 and 4 of the drawings. As shown, base section I 2 of the translating unit includes a casing 30 having an upper plate 3|. Plate 3| supports the driving mechanism, the electrical and mechanical coupling elements, the locating and latching pins, and the parallel ejection mechanism.

The driving mechanism includes a motor 32 which preferably is a constant speed or governor controlled type coupled to a reduction gearing unit generally indicated at 33.. One end of motor 32 is supported by a bracket 34 detachably secured to a bracket 35 in turn secured to plate 3|. Reduction gearing unit 33 is mounted in a composite bracket 38 secured to plate 3| and supports the other end of motor 32. The armature shaft of motor 32 is provided with a worm (not shown) which drives a worm gear 31 secured to a detachable coupling member 38 cooperable with a coupling member 40, shown more particularly in Fig. 4. One of the coupling members may be ing' shaft 40 and engaging gear 46 and the bot-' tom of a socket normally urges gear 66 outwardly,

Intermediate its ends, shaft AI is provided with a spiral gear 46 meshing with a spiral gear 41 on a shaft 68 extending horizontally. Shaft 46 has secured thereto a worm 6i engaging a worm gear 62 on a shaft 53. Shaft 63 extends transversely of casing 30 and is supported in a bracket 60, forming part of bracket 36. A coupling element, such as a spur gear 65 is secured to the outer end of shaft 53 and extends through an aperture 56 in the plate 3|. Through the described gearing arrangement, s aft 68 is rotated at a greatly reduced rate with respect to shaft ti. Gear is arranged for cooperative relation with a mechanical coupling means for one of the reels in magazine I5, and gear 66 is arranged for cooperation with mechanical coupling means for spooling mechanism containedin magazine A mechanical coupling element cooperable with mechanical coupling means for the other reel in magazine i6 is also provided, and comprises a gear 60 similar to the gear 46 and having axially extending teeth 66 rounded at their outer edges. Gear 60 is keyed to a shaft 61 and is normally urged outwardly through aperture 66 in plate ti by a spring 6I surrounding shaft 51 and engaging the bottom of gear 60 and a spring seat 62 mounted in a socket 63 secured to plate II. A nut 66 secures a friction spring 66 to the lower reduced end of shaft 61. Spring 66 thus exerts a drag resisting rotation of shaft 61 for a purpose described more fully hereinafter.

A pair of locating pins 66 and 61 are secured to plate 3i and extend upwardl therefrom for cocperation'with suitable locating apertures in magazine I 5. Plate 3i also has mounted thereon a latching pin 68, shown more clearly in Fig. 7. Pin 6t is provided with an upper tapered surface it and a notch TI cooperable with latching means in magazine I6.

A parallel ejecting mechanism generally indicated at I6 (Fig. 3) forms part of unit I6 and is adapted, upon release of the latch in magazine It, to eject the magazine from unit 20 while maintaining parallel relation therebetween to prevent binding of the magazine on the unit. The parallel ejecting mechanism comprises a bracket 12 secured to plate 3| and having three downwardly extending arms I3. Each arm I! pivotally supportsan ejecting member I4. Each member 14 comprises a substantially vertically extending curved arm 16 extending through an aperture 11 in plate 3|, and a horizontally extending arm 16 provided with a projection 00. All the projections 60 engage a washer BI slidably mounted on a pin 82 secured to bracket I2. A coil spring 83 surrounds pin 62 and engages washer 6| and bracket I2. Coil spring 63 exerts a uniform pressure against arms 16 of members I4 forcing these arms downwardly and the projecting arms I6 through apertures IT in plate ll. The operation of the parallel ejecting mechanism will be described more fully hereinafter.

The forward section II of unit 20 contains suitable electricaland electronic circuit components forthe sound translating system, These electrical and electronic control elements are associated with control switches I8, 2I, "on" light 22, level meter 23, electrical coupling member 24, and microphone jack I'I. Electrical impulses from the sound translating circuit contained in section I I are conducted to the electrical coupling element 85 projecting above the surface of plate 3| and cooperable with electrical plug means in magazine I6. Through coupling element 85 and its associated plug means, theelectrical impulses are conducted to the magnetic translating head in magazine Ili where they are transformed into magnetic impulses that are imposed upon the moving magnetic recording wire in the magazine.

Magazine I6, and its component elements, are shown in more detail in Figs. 5 through 10. The

magazine comprises a base 90 which may be cast of a suitable light metal such as aluminum or an alloy thereof. Base 90 is provided with corner posts 9| having threaded apertures for receiving screws 82 which secure a rectangular cover 93 to the base. By suitable disengagement of screws 92, cover 93 is quickly and easily detachable from base 90 for ready access to'the components of magazine I5. Base 90 is provided with apertures 94, 96 and 06 through which mechanical coupling elements 46 and 60 and electrical coupling element 85 of translating units 20 are adapted to extend into engagement with the mechanical and electrical coupling means, respectively of maga-. zine iii. The magazine is also provided with apertures 91 and 98 cooperable with locating pins 66 and 61, and with an aperture I00, shown in Fig. '7, receiving latching pin 68 of unit 20.

Referring moreparticularlyto Figs. 5and 6, base 90 is provided with a pair of upstanding apertured bosses IOI and I02 which acts as bearing supports for the reeling means I03 and I 06. Two part bearings I05 are disposed in the aperture of each boss IOI, I02, for receiving a pivot comprising a shaft I06 having a flange I0'I and a head I08 provided with a threaded aperture IIIi. Secured to the lower ends of each shaft I06 are mechanical coupling means H5 and I20, each of which comprises an axially toothed gear cooperable respectively with the similar gears 45 and 60 of translatin unit 20. To facilitate such cooperation, the outer edges of the teeth of gears H6, I20 are rounded.

The reels, per se, each comprise a circular disk III of insulating material having central aperturesreceiving the heads I06 of pivots I06 and offset apertures each receiving a pin II2 extending through'the fiber disk and an aperture in flanges I01 of pivots I06. Screw H3 threaded into apertures IIO of pivots I06 secures each disk III to its associated pivot I06. Annular metal members H14 having channel shaped peripheries are secured to each of the disks III. in

r 61 engage bow springs II6, releasing the reels for rotation. As soon as the cartridge is disengaged from the translating unit, the bow springs snap into engagement with the reels to retain the same against relative rotation. This prevents unwinding and possible tangling of magnetic recording wire I25 during periods when the cartridge is disengaged from the associated translating unit, in transit. or stored, and, in effect, is an automatically releasable braking means for each of the magazine reels.

Base 90 is provided with a pair of vertical walls I2I and I22 which act as supports for the pivotally mounted combined spooling mechanism, translating head and erasing head unit, constituting rocker-arm assembly I30. Wall I2I is recessed inwardly from the outer edge of base 90, as shown in Figs. 5 and 7, for a purpose to be described hereinafter. Wall I22 extends parallel to wall I2I and is located adjacent the transverse center of the base. This latter wall also acts as a support for the elapsed time indicating mechanism 25 which includes a needle I23 disposed adjacent the aperture 25 in cover plate 93 of cartridge I5, as shown more clearly in Figs. 1, 7 and 10.

Referring to Figs. 7, 8 and 9, unit I 30 includes a flat plate I24 having vertical ears I26, I21, I28 and I29. The plate is further formed with an aperture I3I for electrical connections of magnetic translating head I40, and with a longitudinally extending arm I32 having a semirounded'projection I33. A bearing pivot I34 is mounted in aperture I25 and engages a recessed bearing I35 mounted in an aperture in wall I2I. Similarly, a recessed bearing I36 is mounted in an aperture in ear I29 and receives a threaded pivot I31 extending through an aperture in wall I22 and provided with a lock nut I38. Plate I24 is thus supported for oscillating movement in a vertical plane with respect to base 90, or in a plane parallel to the axes of reels I03, I04, and thus for oscillating movement with respect to the reels.

Magnetic translating head I40 for recording and reproducing is secured near the outer edge of plate I24, and has a groove I4I through which magnetic recording wire I25 extends. The wire is retained in place in the groove by a spring pressed plate I42 extending across the groove. Referring to Figs. 6 and 9, erasing head or coil I43 is mounted. by means of a bracket I44, on plate I24, and is provided with an aperture I45 through which magnetic wire I25 extends. Under the control of suitable switches on translating unit 20, high frequency potential such as 25 kilocycles is impressed on erasing head I43 for the purpose of wiping out any magnetic impulses on wire I25 as it passes through the erasing head.

. in a manner well known to those skilled in the operation of the reels, to prevent breaking or damage of the recording wire. The pair of wire feeding rocker-arms I45 and I41 are mounted on bracket plate I24, as shown more particularly in Figs. 8 and 9. Rocker-arm I45 comprises a tube I48 havinga flange I50 riveted or otherwise secured to ear I28 of plate I24. A forked member I5I extends into the hollow outer end I52 of sleeve I48 and rotatably supports a grooved pulley I54.

Rocker-arm I41 comprises a sleeve member I55 having a flange I55 suitably secured to ear I21 of plate I24. Sleeve I55 is provided with a longitudinally extending slot I51 slidably receiving a pin I58 secured to a plunger I50 disposed in the sleeve. A spring I6I extends between the outer end of sleeve I55 and a forked member I62 rotatably supporting a grooved pulley I53. Wire I25 passes over pulleys I 54, I53 which, as may be seen more clearly in Figs. 5, 6 and 9, are disposed adjacent reels I03 and I04, respectively, and as near as possible to the outer ends of the magazine unit. By having the pulleys disposed at the extreme distance from recording head I40, the greatest length Of wire I25 between bends is provided, thereby substantially decreasing the possibiiity of weakening or breakage of the wire due to being bent at too sharp an angle of curvature. The shock absorbing mechanism I 41, including spring I6I, prevents damage or breaking of the wire due to the shock of starting or stopping rotation of reels I03, I04.

Spooling mechanism I30 is oscillated by means of a reentrant cam I 55 secured to a spur gear I55 mounted on a pivot screw I51 extending through wall I2I of base 90. Gear I65 is disposed adjacent an aperture I58 in base 90, which aperture, when magazine I5 is placed in operative relation with translating unit 20, is aligned with aperture 55 of unit 20. Accordingly, gear 55 secured to the gear reduction unit 33 will extend through aperture I58 and mesh with gear I65 to operate cam I65 at a reduced rate with respect to the rate of rotation of reels I03, I04. Cam I55 is designed to oscillate spooling mechanism I30 at such a rate that wire I25 of a given diameter, is fed onto and off of reels I03, I04 in uniform layers. Cam I55 is engaged by a cam follower constituting rounded projection I33 of extension I32 01 plate I24. Follower I 33 is maintained in engagement with the cam surface by leaf spring I10 secured to base 50 and engaging the underside of arm I32. As gear I55 is rotated by gear 55, cam I65 oscillates rocker-arm I32, and thus spooling mechanism I30, providing uniform spooling of wire I25 by pulleys I54, I53 onto reels I03 or I04.

Electrical coupling means such as an electrical socket "I is mounted on base adjacent aperture therein. Accordingly, when magazine I5 is placed in operative relation with unit 20, electrical coupling element 85 of unit 20 will project through aperture 56 into electrical cooperation with socket member I1 I. For the sake of simplicity, the electrical circuit connections have not been illustrated in the drawings. Suitable electrical connections extend between socket I1I, translating head I 40 and erasing head I43, through aperture It in plate I24, as will be understood by those skilled in the art.

The elapsed time indicating means 25 comprises an insulating block I12 having an elongated slot I13 through which extends a shouldered stud I14 threaded into wall I22. A pair of bowed springs I15, I15 are secured to either end of block I12 and engage the wire on reels I03, I04 respectively. As the wire is fed from one reel to the other through recording head I40 and erasing head I43, indicator 25 is reciprocated back and forth with respect to the aperture 25 and cover plate 93. jacent aperture 25, indicates the amount of time or remaining wire I25. Needle I23 comprises an L-shaped member secured to block I12 by screws I11.

A releasable latching means I80 is provided in magazine I5 for ready disengagement thereof from unit 20, in cooperation with parallel ejecting means of unit 20. This latching means shown in Figs. 5 and 7 comprises an, I.-shaped ba I8I hav- Thus, reference to a suitable scale ad- 9 ing a vertical arm I02 disposed adjacent the recess in wall III of; base 00, and a horizontal arm I33 extending through slots in walls HI and I22. The inner end of arm I33 is provided with an aperture I04 substantially aligned with aperture I in base 00. A spring I05 normally maintains latching bar I00 in its outer position. when magazine I5 is placed on unit 20, the sloping surface of latching pin 00 moves bar I I0 inwardly against the force of spring I05 until such time as the inner end of the bars snaps into notch II of the latching pin as shown in Fig. '1. Magazine I5 is thereupon locked upon unit 20, with the ejecting arms it forced inwardly against the force of associated spring 03. To release magazine I 5 from unit 20, bar l00on the side of magazine I5 is gripped and pressed inwardly. releasing its inner end from notch 11- of latching pin 00. Spring 03 thereupon motivates ejecting arms 10 to force magazine II a short distance away from unit 20, meanwhile maintaining the magazine base disposed parallel to the upper surface of unit 20. Magazine I5 may thereupon be quickly removed irom unit and a new one readily placed thereon.

As seen in Fig. 5, brush means I" and I" are provided adjacent each reeling means I03, I04

and comprise spring contact members Ill and I30 secured to base 80 of magazine I5 through the medium of insulating blocks I 0i and I02.

. Contact members "8,100 engage metal reel elements II4.

Reel elements 4 are in-electrical contact with the wire I25. Brushes I00, I01 are included in an electric supervisory circuit including the motor drive, controlling operation of the components of unit 20. Should the wire I break, such supervisory circuit is opened to operate a warning signal and/or stop operation of the system.

The operation 01' the apparatus of the present invention is as follows. Wire I25 is first wound up on "pay ou reel I04. by a suitable rewinding the wire in uniiorm layers onto reel I03.

over pulleys I54 and I83. The spring IIiI associated with pulley I03 takes up any shock to the wire inhibiting its breakage, and maintains the moving wire substantially in uniform tautness.

At the start of unreeling of wire I25 from spool I04 indicating needle I23 of elapsed time indicator." will be in its right-hand position, referring to Fig. 5 as a reference.

Spooling mechanism unit I30 will be oscillated at a uniform rate, slower than the rate of rotation 0! reel I03, by gear reduction unit 33 to feed The spooling mechanism oscillates at such a rate that the oscillation is reversed each time one layer is completely wound on reel I03. A uniform spooling is thus effected upon the "take on" reel I03. During rewind operation, the reverse occurs, with the uniform spooling effective on the other reel. namely I04. i

The magnetic translation with respect to the reeled wire I25 may be recording as described, or

reproducing if desired. As the reeling proceeds,

indicating needle I23 will move from the far right position shown in Fig. 5 to the far left position, due to the wire being wound oil reel I04 and wound ontoreel I03, thereby moving the indicator to the left by engagement of springs I15, I10 with the wire on each of the reels, to properly indicate the condition of the wire on the spools.

When it is desired to remove the magazine, the

' operator places his hand on it, pressing latching chanical coupling means H5, I56 and I20 of magazine I5. Similarly, electrical coupling element 85 will enter into electrical cooperation with electrical coupling means III of magazine I5. In the event that either meshing pair of the radially toothed gears is not properly aligned, the rounded edges or the teeth of these gears, in cooperation with springs 43 and GI, will permit the small relative rotation and axial movement of gears and 60 to obtain meshing engagement with associated gears I I5 and I20. Through actuation of switches" and 2|, the sound translating elements of unit 20 are conditioned to translate sound impulses from microphone I3 into electrical impulses which are transmitted to recording head I40 and converted therein to magnetic impulses imposable on .wire I25. Motor 32, through bar I00 inwardly with his fingers. This releases the latching bar from latching stud 68 of unit 20. The parallel ejecting members I6 thereupon push cartridge I5 upwardly from unit 20 and the magazine may be quickly moved therefrom and another magazine readily replacing it.

The magazine removed from unit 20 and containing a recording may be quickly and compactly stored, due to its flat sided construction, for filing purposes and later used on a. sound reproducing unit wher the wire I25 is first rewound, and then played. 'Access to the interior of cartridge I5 for repair or replacement of parts is conveniently afforded by ready removal of cover 03 from base 90 through disengagement of screws 02. tive in service, its ready replacement with a spare renders any repair thereof in the field unnecessary except at a depot or back at the base. The

rugged construction of the system and maga- While a specific embodiment of the invention has been described to illustrate the application of the principles thereof, it will be apparent to those skilled in the art that the invention may be otherwise embodie'd. without departing from such principles.

What is claimed is:

' 1. A magazine adapted for interchangeable sound translating cooperation with a magnetic sound translating unit and comprising a pair of reels rotatably mounted for traversing a magnetic recording wire; spooling mechanism for feeding the wire uniformly onto and from said reels, said spooling mechanism comprising a memberivotally supported between said reels for oscillation about an axis perpendicular to a plane including theaxes of said reels and elements connected to said member and projecting toward each of said jreels for guiding the magnetic wire between said However, should a magazine become dei'ec- 11 from said reels; and externally accessible mechanical coupling means associated with each of said reels for rotating them in synchronism with the oscillating means.

2. A magazine adapted for interchangeable sound translating cooperation with a magnetic sound translating unit and comprising a pair of reels rotatably mounted for traversing a magnetic recording wire; spooling mechanism for feeding the wire uniformly onto and from said reels, said spooling mechanism comprising a member pivotally supported between said reels for oscillation about an axis perpendicular to a plane including the axes of said reels and a pair of elongated arms connected to said member and projecting toward each of said reels for guiding the magnetic wire between said reels, a pulley mounted in the outer end of each arm adjacent the associated reel for guiding the magnetic wire between said reels and a cam follower projecting from said member; a reentrant cam rotatably mounted in said magazine and operatively engaging said cam follower for oscillating said member and arms whereby said pulleys will feed the wire in uniform layers onto and from said reels; and externally accessible mechanical coupling mean operatively associated with each of said reels and with said cam.

3. A magazine adapted for interchangeable sound translating cooperation with a magnetic sound translating unit and comprising a magnetic translating head; a pair of reels rotatably mounted for traversing a magnetic wire with respect to said translating head; spooling mechanism for feeding the wire uniformly onto and from said reels, said spooling mechanism com prising a member pivotally supported between said reels for oscillation about an axis perpendicular to a plane including the axes of said reels, said translating head being mounted on said member for oscillation as a unit therewith, and elements connected to said member and projecting toward each of said reels for guiding the magnetic wire between said translating head and said reels; means for oscillating said member and elements to feed the wire in uniform layers onto and from said reels; and externally accessible mechanical coupling means associated with each of said reels for rotating them in synchronism with the oscillating means.

4. A magazine adapted for interchangeable sound translating cooperation with magnetic sound translating unit and containing a magnetic translating head; a pair of rotatably mounted reels for traversing a magnetic wire with respect to said translating head; spooling mechanism for feeding the wire uniformly onto and from said reels, said spooling mechanism comprising a plate pivotally supported between said reels for oscillation about an axis perpendicular to a plane including the axes of said reels, said translating head being mounted on said plate for oscillation as a unit therewith, arms connected to said plate projecting toward each of said reels, and a pulley mounted in the outer end of each arm adjacent the associated reel for guiding the magnetic wire between said translating head and said reels; means for. oscillating said plate and arms whereby said pulleys will feed the wire in uniform layers onto and from said reels; and externally accessible mechanical coupling means associated with each of said reels for rotating them in synchronism with the oscillating means.

5. A magazine adapted for interchangeable sound translating cooperation with a magnetic sound translating unit and containing a pair of rotatably mounted reels for traversing a magnetic wire; spooling mechanism for feeding the wire uniformly onto and from said reels, said spooling mechanism comprising a plate pivotally supported between said reels for oscillation about an axis perpendicular to a plane including the axes of said reels, arms connected to said plate projecting toward each of said reels, and a pulley mounted in the outer end of each arm adjacent the associated reel for guiding the m etic wire between said reels; means for oscillating said plate and arms whereby said pulleys will feed the wire in uniform layers onto and from said reels; and externally accessible mechanical coupling means associated with each of said reels for rotating them in synchronism with the oscillating means; one of said arms comprising a pair of telescoping members and a spring urging said members to their extended position, said spring absorbing uneven tensions on the wire.

6. A magazine adapted for interchangeable sound translating cooperation with magnetic sound translating unit and containing a magnetic translating head; a pair of rotatably mounted reels for traversing a magnetic wire with respect to said translating head; spooling mechanism for feeding the wire uniformly onto and from said reels, said spooling mechanism comprising a plate pivotally supported between said reels for oscillation about an axis perpendicular to a plane including the axes of said reels, said translating head being mounted on said plate for oscillation as a unit therewith, arms connected to said plate projecting toward each of said reels, and a pulley mounted in the outer end of each arm adjacent the associated reel for guiding the magnetic wire between said translating head and said reels; means for oscillating said plate and arms whereby said pulleys will feed the wire in uniform layers onto and from said reels; and externally accessible mechanical coupling means associated with each of said reels for rotating them in synchronism with the oscillating means; one of said arms comprising a pair of telescoping members and a spring urging said members to their extended position, said spring absorbing uneven tensions on the wire.

7. A magazine adapted for interchangeable sound translating cooperation with a magnetic sound translating unit and comprising a casing containing a magnetic translating head; a pair of reels rotatably mounted in said casing for traversing a magnetic wire with respect to said translating head; spooling mechanism for feeding the wire uniformly onto and from said reels, said spooling mechanism comprising a late pivotally supported between said reels for oscillation about an axis perpendicular to a plane including the axes of said'reels, said translating head being mounted on said plate for oscillation as a unit therewith, a pair of elongated arms connected to said plateand projecting toward each of said reels, a pulley mounted in the outer end of each arm adjacent the associated reel for guiding the magnetic wire between said translating head and said reels, and a cam follower projecting from said plate; a reentrant cam rotatably mounted in said casing and operatively engaging said cam follower for oscillating said plate and arms whereby said pulleys will feed the wire in uniform layers onto and from said reels; externally accessible mechanical coupling means operatively associated with each or said reels and lating head; spooling mechanism for layer wind-' in the wire uniformly onto and from said reels, said spooling mechanism comprising a member pivotally supported between said reels for oscillation about an axis perpendicular to a plane including the axes of said reels, said translating head being mounted on said member for oscillation as a unit therewith, a pair of elongated arms connected to said member and projecting toward each of said reels, a guide mounted in the outer end of each arm adjacent the associated reel for guiding the magnetic wire between said translating head and said reels, and a cam follower projecting from said mechanism; a reentrant cam rotatably mounted in said casing and operatively engagin said follower for oscillating said member; resilient means maintaining said cam follower in engagement with said cam whereby said guides will feed the wire in uniform layers onto and from said reels; externally accessible me chanical coupling means operatively associated with each of said reels and with said cam; and externally accessible electrical coupling means in electric circuit connection with said translating head; at least one of said arms comprising a pair of telescoping elements and a spring urging said elements to their extended position, said spring absorbing uneven tensions on the wire; and all of said coupling means being disposed substantially within said casing whereby said magazine is adaptedfor-compact fiat storage.

9. A magazine adapted for interchangeable sound translating cooperation with a magnetic sound translating unit comprising a casing; a pair of reels-rotatably mounted in said casing for traversing a-magnetic wire; a bowed spring aligned with an aperture in the base of said casing normally engaging one of said reels and normally restraining rotation thereof when the mag azine is disengaged from the translating unit to prevent displacement of the wire, said spring being automatically disengageable from said reel when the magazine is placed in operative relation with the translating unit by entry of a pin on the unit through said aperture into abutment with'said spring; and externally accessible mechanical coupling means operatively associated with each of said reels; said coupling meansv being disposed substantially within said casing whereby said magazine is adapted for compact fiat storage.

10. A magazine adapted for interchangeable sound translating cooperation with a magnetic sound translating unit comprisin a casing containing a magnetic translating head; a, pair of .reels rotatably mounted in said casing for traversing a magnetic wire with respect tosaid translating head; a bowed spring aligned with an anerture inthe base of said casing normally engaging one of said reels and normally restraining rotation thereof when the magazine is disengaged from the translating unit to prevent disthrough said aperture into abutment with said spring; externally accessible mechanical coupling means operatively associated with each of said reels; and externally accessible electrical coupling means in electric circuit connection with said translating head; all of said coupling means being disposed substantially within said casing whereby said magazine is adapted for compact flat storage.

11. A magazine adapted for interchangeable sound translating cooperation with magnetic sound translating unit and containing a magnetic translating head; a pair of rotatably mounted reels for traversing a magnetic wire with respect to said translating head; spooling mechanism for feeding the wire uniformly onto and from said reels. said spooling mechanism comprising a plate pivotally supported between said reels for oscillation about an axis perpendicular to a plane including the axes of said reels, said translating head being mounted on-said plate for oscillation as a unit therewith, arms connected to said plate projecting toward each of said reels, and a pulley mounted in the outer end of each arm adjacent the associated reel for guiding the magnetic wire between said translating head and said reels; means for oscillating said plate and arms whereby said pulleys will feed the wire in uniform layers onto and from said reels; brake means normally restraining rotation of said reels when the magazine is disengaged from the translating unit to prevent displacement of the wire, said brake means being disengagea'ble from said reels by placement of the magazine in operative relation with the translating unit; externally accessible mechanical coupling means operatively associated with each of said reels and with the oscillating means; and externally accessible electrical coupling. means-in electric circuit connection with said translating head.

12. A magnetic sound translating system comprising a magazine, a pair of reels rotatably mounted in saidmagazine for traversing a magnetic wire, spooling mechanism for feeding the wire uniformly onto and from said reels, first externally accessible mechanical coupling means operatively associated with each of said reels, and second externally accessible mechanical coupling means operatively associated with said spooling mechanism; a sound translating unit containing driving mechanism, including reduction gearing, sound translating means, a first mechanical coupling element operatively associated with said driving mechanism, and a second mechanical coupling element operatively associated with said reduction gearing; said magazine being detachably cooperative with said unit by engagement of said first and second coupling means with said first and second coupling elements to establish driving relation between said driving means and reels and between said gearing and spooling mechanism to operate the latter at a reduced rate relative to said reels; latching means mounted in said magazine; a latching element mounted in said unit and adapted to engage said latching means, when said magazine is placed on said unit, to lock said magazine to said unit; and ejecting means mounted in said placement of .the' wire, said spring being auto matically disengageable from said reel when the magazine is placed in operative relation with the translating unit by entry of a pin on the unit unit and automatically operable, upon manual release of said latching means from said latching element, to displace said magazine from said unit. 13. A magnetic sound translating system comprising amagazlne containing a magnetic translating head, a pair of reels rotatably mounted in said magazine for traversing a magnetic wire with respect to said translating head, spooling mechanism for feeding the wire uniformly onto and from said reels, first externally accessible mechanical coupling means operatively associated with each of said reels, second externally accessible mechanical coupling means operatively associated with said spooling mechanism, and externally accessible electrical coupling means in electric circuit connection with said translating head; a magnetic sound translating unit containing driving mechanism, including reduction gearing, and sound translating means, a first mechanical coupling element operatively associated with said driving mechanism, a second mechanical coupling element operatively associated with said reduction gearing and an electrical coupling element for circuit connection with said trans-- lating means; said magazine being detachably cooperative with said unit by engagement of said first and second coupling means with said first and second coupling elements to establish driving relation between said driving means and reels and between said gearing and spooling mechanism to operate the latter at a reduced rate relative to said reels, and engagement of said electrical coupling means with said electrical coupling element to electrically connect said translating head with said translating means; latching means mounted in said magazine; a latching element mounted in said unit and adapted to engage said latching means, when said magazine is placed on said unit, to lock said magazine to said unit; and ejecting means mounted in said unit and automatically operable, upon manual release of said latching means from said latching element, to displace said magazine from said unit.

14. A magnetic sound translating system comprising a magazine containing a magnetic translating head, a pair of reels rotatably mounted at each end of said magazine for traversing a mag-, netic wire with respect to said translating head, spooling mechanism for'feeding the wire uniformly onto and from said reels, an axially toothed coupling gear secured for rotation with each of said reels and aligned with an aperture in the base of said magazine, a spur gear operatively associated with said spooling mechanism and having a plane of rotation aligned with a lot in the base of said magazine, and externally accessible electrical coupling means in electric circuit connection with said translating head and aligned with an aperture in the base of said magazine; and a magnetic sound translating unit containing driving mechanism, including reduction gearing, and sound translating means, a first shaft rotatable by said driving mechanism, a second shaft rotatably mounted in said unit, friction means restraining rotation of said second shaft, an 'axially toothed coupling gear slidably mounted on each of said shafts and rotatable therewith, resilient means urging each of said last named gears to project above the upper surface of said unit, a spur gear operable by said reduction gearing and projecting above the upper surface of said unit, and an electrical coupling element in circuit relation with said translating means and projecting above the upper surface of said unit; said magazine being detachably cooperative with said unit by engagement of the coupling gears and spur gear of said magazine with the coupling gears and spur gear of said unit, respectively, to establish driving relation between said driving mean and reels and beto electrically connect said translating head with said translating means; the coupling elements of said unit entering said apertures and said slot to engage the coupling means of said magazine.

15. A magnetic sound translating system comprising a magazine containing a magnetic translating head, a pair of reels rotatably mounted in a d azine for traversing a magnetic wire with respect to said translating head, spooling mechanism for feeding the wire uniformly onto and from said reels, an axially toothed coupling gear secured for rotation with each of said reels and aligned with an aperture in the base of said magazine, a spur gear operatively associated with said spooling mechanism and having a plane of rotation aligned with a slot in the base of said magazine, externally accessible electrical coupling means in electric circuit connection with said translating head and aligned with an aperture in the base of said magazine, and a pair of bowed springs each aligned with a locating aperture in the base of said magazine and each normally engaging one of'said reels and restraining rotation thereof when said magazine is disengaged from a translating unit, to prevent displacement of the wire; and a sound translating unit containing driving mechanism, including reduction gearing, and sound translating means, a first shaft rotatable by said driving mechanism, a second shaft rotatably mounted in said unit, friction means restraining rotation of said second shaft, an axially toothed coupling gear slidably mounted on each of said shafts and rotatable therewith, resilient means urging each of said last named gears to project above the upper surface of said unit, a spur gear operable by said reduction gearing and projecting above the upper surface of said unit, an electrical coupling element in circuit relation with said translating means and projecting above the upper surface of said unit and locating pins projecting from the upper surface of said unit; said magazine being detachably cooperative with said unit by engagement of the coupling gears and spur gear of said magazine with the coupling gears and spur gear of said unit, respectively, to establish driving relation between said driving means and reels and between said gearings and spooling mechanism, to operate the latter at a reduced rate relative to said reels, and engagement of said electrical coupling means with said electrical coupling element to electrically connect said translating head with said translating means; said locating pins entering said locating apertures and engaging said bow springs to disengage the same from said reels.

. 16. A magnetic sound translating system comprising a magazine containing a magnetic translating head, a pair of reels rotatably mounted at each end of said magazine for traversing a magnetic wire with respect to said translating head, spooling mechanism for feeding the wire uniformly onto and from said reels, first externally accessible mechanical coupling means operatively associated with each of said reels, second externally accessible mechanical coupling means operatively associated with said spooling mechanism, externally accessible electrical coupling means in electric circuit connection with said translating head, a latching bar slidable transversely of said magazine and having an aperture in its inner end substantially aligned with an aperture in the base of said magazine and resilient means normally urging said bar outwardly from said magazine; and a sound translating unit containing driving mechanism, including reduction gearing, and sound translating means, a first mechanical coupling element operatively associated with said driving mechanism, a second mechanical coupling element operatively associated with said reduction gearing, an electrical coupling element in circuit relation with said translating means, a pin projecting above the upper surface of said unit and having a sloping surface and a notch formed below said surface and ejecting means operable to displace said magazine from said unit; said magazine being detachably cooperative with said unit by engagement of said first and second coupling means with said first and second coupling elements to establish driving relation between said driving means and reels and between said gearing and spooling mechanism to operate the latter at a reduced rate relative to said reels, and engagement of said electrical coupling means with-said electrical coupling element to electrically connect said translating head with said translating means; said pin entering the apertures in the magazine base and in said bar, the sloping surface of said pin moving said bar against said spring until said bar enters said notch to latch the magazine on the unit; said ejecting means automatically displacing said magazine from said unit upon manual release of said bar from said notch.

17. A magnetic sound translating system comprising a magazine containing a magnetic translating head, a pair of reels rotatably mounted at each end of said magazine for traversing a magnetic wire with respect to said translating head, spooling mechanism for feeding the wire uniformly onto and from said reels, first externally accessible mechanical coupling means operatively associated with each of said reels, second externally accessible mechanical coupling means operatively associated with said spooling mechanism, externally accessible electrical coupling means in electric circuit connection with said translating head and latching means; a sound translating unit containing driving mechanism, including reduction gearing, and sound translating means, a first mechanical coupling element operatively associated with said driving mechanism, a second mechanical coupling element operatively associatedwith said reduction gearing, an electrical coupling element in aircuit relation with said translating means. a latching element adapted to engage said latching means, when said magazine is placed on said unit, to lock said magazine to said unit, a plurality of bars pivotally mounted in said unit and extending radially at equal angular intervals from the center thereof, the outer ends of said bar projecting upwardly through apertures in the upper surface of said unit and spring means engaging the inner ends of all of said, bars; said magazine being detachably cooperative with said unit by engagement of said first and second coupling means with said first and second coupling elements to establish driving relation between said driving means and reels and between said gearing and spooling mechanism to operate the latter at a reduced rate relative to said reels, and engagement of said electrical coupling means with said electrical coupling element to electricslly connect said translating head with said translating means: said spring means being com- 18 pressed by inward movement of the outer ends of said bars When said magazine is latched to said unit, and urging such outer ends outwardly to uniformly displace said magazine from said unit upon manual release of said latching means from said latching element.

18. A magnetic sound translating system comprising a magazine containing a magnetic translating head, a pair of reels rotatably mounted at each end of said magazine for traversing a magnetic wire with respect to said translating head, spooling mechanism for feeding the wire uniformly onto and from said reels, first externally accessible mechanical coupling meansoperatively associated with each of said reels, second externally accessible mechanical coupling means operatively associated with said spooling mechanism, externally accessible electrical coupling means in electric circuit connection with said translating head. a latching bar slidable transversely of said magazine and having an aperture in its inner end substantially aligned with an aperture in the base of said magazine and resilient means normally urging said bar outwardly from said magazine; and a sound translating unit containing driving mechanism, including reduction gearing, and sound translating means, a first mechanical coupling element operatively associated with said driving mechanism, a second mechanical coupling element operatively associated with said reduction gearing, an electrical coupling element in circuit relationwith said translating means, a pin projecting above the upper surface of said unit and having a sloping surface and a notch formed below said surface, a plurality of bars pivotally mounted in said unit and extending radially at equal angular intervals from the center thereof, the outer ends of said bars projecting upwardly through apertures in the upper surface of said unit and spring means engaging the inner ends of all of said bars; said magazine being detachably cooperative with said unit by engagement of said first and second coupling means with said-first and second coupling elements to establish driving relation between said driving means and reels and between said gearing and spooling mechanism to operate the latter at a reduced rate relative to said reels, and engagement of said electrical coupling means with said electrical coupling element to electrically connect said translating head with said translating means; said pin entering the. aperture in the magazine base and in said bar, and the sloping surface thereof moving said bar against said spring until said bar enters said notch to latch the magazine on the unit and said spring means being, compressed by inwardmovement of the outer ends of said bars .when said magazine is latched to said unit, and urging such outer ends outwardly to uniformly displace said magazine from said unit upon manual release of said latching bar from said notch.

, HERMAN NYGAARD.

REFERENCES crr'an The following references are of record in the file of this patent:

nnrrn STATES PATENTS Name Date 1,123,147 Sherman 29, 1914 1 1,685,784 Kornauer Apr. 10, 1928 2,364,556 Somers Dec. 5, 1944 2,321,812 Heller et al. June 15, 1943 

